Apparatus for spraying a plurality of fluids



M. E. HANSEN Nov. 23, 1943.

APPARATUS FOR SPRAYING A PLURALITY 0F FLUIDS Original Filed May 12, 1934Patented Nov. 23, 1943 Merrill E. Hansen, Silver Lake, Ohio, assignor toAmerican Anode Ina, Akron, Ohio, a corporation of Delaware Originalapplication May 12, 1934, semi No.

725,306. Divided and this application November 15, 1940, Serial No.365,779

17 Claims.

This invention relates to a method and apparatus for-applying temporaryprotective coatlugs to articles or parts of articles formed of metal,wood, fabric, and the like, and especially to polished metal surfacessuch as chrome-plated, nickel-plated and other bright metal surfaces,and to upholstery, shoes, or other articles formed in whole or in partof material likely to be soiled, scuffed or otherwise damaged duringmanufaca further object of the invention to provide means for protectingeasily damaged shoes and parts thereof during manufacture and storage.It is also an object of the invention to provide means for applying acoating of a coagulable aqueous dispersion of rubber or similarmaterial, such as rubber latex, to a normally penetrable fibrous articlewithout substantial penetration of the article by the dispersion andwithout the usual ture and storage, and to other articles where aconsequent tenacious adhesion to the fabric of temporary protectivecoating is of value. the dried coating. Another object of the inven-This application is a division of my co-pendtion is to provide novelapparatus for applying ing application, Serial No. 725,306, filed May12, latex rubber coatings to articles, and also to-pro- 1934, now U. S.Patent No; 2,249,205, granted vide novel apparatus for simultaneouslyspraying July 15, 1941, and intimately mixing two or more fluids.

It has heretofore been proposed to coat arti- These and other objects ofthe invention are cles with liquid rubber latex and to dry the latexattained, in general, by applying to the article to form protectivecoatings upon the articles, but to be coated, a coagulable aqueousdispersion of this proposed method has been limited in its aprubber orsimilar material, which for convenience plication to the coating ofarticleswhich are not will be referred to hereinafter simply as latex,

damaged by contact with the aqueous vehicle of the latex and which havesurfaces to which the dried latex does not adhere so tenaciously as torender stripping of the coating unduly difficult shoe uppers because thefabric of the uppers frequently is spotted by the aqueous vehicle of thelatex and furthermore the dried latex rubber film adheres to the fabricso tenaciously that stripping of the coating is prohibitively diflicult,and also because when the coating is stripped the arrangement of thesurface fibers is disturbed to such a degree as to impair the appearanceof the shoe and accordingly materially to reduce the value thereof.Similar difficulties have been encountered when latex coatings were aplied to other articles having easily damaged surfaces.

It is accordingly an object of this invention to provide economicalmeans for applying adherent in finely divided form and in at least apartially coagulated condition, to produce upon the article an adherentbut non-penetrating and strictly superficial coating of latex rubber orlike maorimpossible, or to result in damage tothe article terial whichdoes not in any way damage the by reason of disturbance of its surfacecharacsurface of the coated article. More specifically, teristics by thestripping operation. For examthe latex coating is applied by sprayingliquid ple, in the manufacture of certain types of womlatex toward thearticle and treating the latex ens' shoes which include uppers formed ofexwith coagulant before it has reached the surface pensive textilefabrics, it is essential that the of the article; In a preferredembodiment, this uppersbe carefully protected to prevent their beisaccomplished by producing in front of the coming soiled or otherwisedamaged during mam article to be coated a cloud composed of fluidufacture of the shoe. Ordinary latex protective coagulant in finelydispersed form, and then coatings applied according to methodsheretofore spraying the latex through the cloud and onto known are notsatisfactory for protecting such the article, so that the sprayed latexglobules are intimately mixed and uniformly treated with coagulantbefore they reach or are deposited upon the surface of the-article beingcoated. As will hereinafter appear, it is highly essential that no latexbe applied to the article unless the latex has first been treated withcoagulant, and the invention accordingly includes means designed toinsure application only of latex which has first been mixed and treatedwith coagulant.

To clarify details of the invention and to indicate a preferred mode ofperforming the same, the application of a temporary protective coatingto a partially built shoe and a preferred apparatus for applying thecoating will now be described, reference being had to the accompanyingdrawing of which,

Fig. 1 is a perspective view showing a portion of a shoe mounted forapplication of a protective coating, and also showing in diagrammaticform apparatus for applying the protective coating accles; and

Fig. 3 is an elevation of a modified spray head for use on a spray gunsimilar to that of Fig. 2.

In a specific example of the invention, a portion. of a woman's shoesuch as the upper I is formed of relatively expensive and easily damagedfabric such as satin, and the upper is lasted upon a conventional last Il as is usual in shoe manufacture. The last then is mounted forapplication to the upper of a protective covering, preferably by placingthe last upon a sole-protecting shield l2 consisting of a sheet metalbase I3 and a superposed layer of resilient material, preferably spongerubber shaped to conform to the sole of the last and to cover andprevent application of latex to portions of the upper material turnedunder the last, to which the shoe sole is later to be adhered. The lastpreferably is held in place and is urged against the resilient shield asby means of a plunger l5 resiliently urged against the top of the lastby a coil spring IS, the plunger being slidably mounted upon a suitablesupport II. The shield l2 may if desired be secured to the end of avertical shaft 18 mounted for rotation upon a,thrust bearing I3 carriedby a frame 20, and the shaft may be rotated through miter gears 2|, 2|and a drive shaft 22 driven by a suitable source of power (not shown).Thus, it is seen that a lasted shoe upper mounted upon the shield I2 maybe held securely in place and meanwhile rotated in a horizontal planefor application of a protective coating to the upper. In an alternativeapparatus, a number of similar shields may be mounted upon a travelingconveyor to carry lasted uppers or shoes past apparatus for applyingprotective coatings.

After the lasted upper is mounted as described, latex 23 in at least apartially coagulated condition is applied to the upper as by means ofspraying apparatus 24 hereinafter more fully described, and theapplication of the latex is continued until a coating thereof is formedcompletely .covering the exposed surface of the upper, afterv which thelatex is dried to produce anadherent but easily removable protectivecoating. Manufac- -ture of the shoe then is continued in th usual manneruntil its completion, when the protective coating may be stripped fromthe shoe with ease' to expose the satin upper in an undamaged andperfectly clean condition. Alternatively, the coating may be allowed toremain upon the finished shoe to protect it from damage during storage.

It has been found that if latex applied to the fabric composing theupper has been at least partially coagulated as hereinabove described,it does not penetrate the fabric to any substantial extent but forms asuperficial coating which is sumciently adherent to maintain its placeduring subsequent manufacture of the shoe, but which does not adherewith such tenacity as to damag the surface of the fabric when it isstripped therefrom nor to render the stripp' unduly difficult. Nor isthe most sensitive f bric spotted, discolored, or otherwise damaged bsuch application of partially coagulated latex is often the case whenuncoagulated latex is applied directly to the fabric and dried thereon.It is highly desirable, therefore, to apply only latex which has been atleast partially coagulated and to avoid application to th fabric orother easily damaged surface of the slightest amount of latex which hasnot been treated with coagulant; This is accomplished by providing meansfor producing a cloud of coagulant before the article to be coated, andthen spraying latex through the cloud and onto the article, and byproviding controlling means so designed as to make spraying of the lateximpossible except after and while the cloud pro-' ducing means is inoperation.

Such apparatus indicated generally by the numeral 24 comprises forexample a compressed air operated latex spray gun 25, having aconnecting hose 26, fitted with a valve 21, leadingdzt'fareservoir 2Bforliquid latex, and also having a compressed air connection 29 leading toa controlling a containing a fluid coagulant, the gun 33. also having anair connection 31 leading to the valve 30 and thence-to the supply ofcompressed air. The two spray guns are mounted upon the bracket 3| atsuch an angle to each other that fluid streams of latex and of coagulantissuing from their respective spray jets 38 and 39 will converge at apoint preferably a few inches from the jets. The valve 30 is designed toPermit air to fiow to the coagulant spray before it fiows to the latexspray and to stop air flow to the latex spray before it is stoppedflowing to the coagulant spray and accordingly to insure that thecoagulant or cloud producing spray gun always shall be operative beforeand throughout the time the latex spray is operative. For purposes ofillustration the valve 30 has been shown as comprising a tubular fluidtight cylinder 40 connected at one end by means of a tube 4| to a supplyof compressed air. The cylinder is provided with a pair of valve ports42, 43 longitudinally spaced apart along the cylinder wall, the port 42nearest the air inlet being connected to the coagulant spray gun by thehose 3'! while the second port 43 further removed from the air inlet isconnected by the hose 29 to the latex spray gun. A piston 44 mountedupon a piston. rod 45 and adapted to slide within the cylinder isprovided for controlling fiow of air through the-valve; The piston 44 isprovided with a longitudinal channel 46 to equalize the pressures on thetwo sides of the piston for the purpose of permitting its easy movementwithin the valve cylinder, and the length of the piston is such thatwhen it is in the closed position (at the air inlet end of th cylinder)both valve ports 42 and 43 are closed so that no air flows to either ofthe two spray guns. As the piston is moved away from the closedposition, air is first admitted to the coagulant spray gun 33therebyproducing a spray on cloud of coagulant before the spray guns(the valve 35 controlling the flow of fluid coagulant to the gun havingbeen opened in the meantime) and thereafter, air is admitted to thelatex spray gun 25 which projects liquid latex (the valve 27 also havingbeen opened) through the coagulant cloud and onto the shoe upper. Whenthe piston 44 is returned to the closed position after the coating hasbeen applied to the shoe, the air supply is first cut off from the latexspray and then assure coagulant. The spraying apparatus has been shownin diagrammatic form for simplicity of illustration and ease ofdescription, and it is ap- P rent that more compact and convenientapparatus embodying the essential features of the present invention ashereinabove indicated may be devised by a skilled artisan.

One example of such refined spraying apparatus is illustrated in Fig. 2and comprises a 9m gun 50 resembling in its general construction sprayguns now available commercially. but embodying additional novel featureswhich adapt the gun for, use in the present method of applying temporaryprotective coatings. The gun 50 comprises a cast metal frame consistingof a handle and a "barrel" portion 52 extending from one end of thehandle and generally at right angles thereto as in well known types ofspray guns. At the end of the barrel portion is provided afrusto-conical projection 53 in the center of which in close mutualrelationship are two fluid jets 54, 55, which communicate by means ofseparate fluid channels 55, 51, with external connections 58, 59, whichmay lead to fluid reservoirs (not shown) as for example reservoirscontaining respectively, fluid coagulant and liquid latex, or otherfluids which are to be sprayed together. A removable, cylindrical cap 50is fltted over the projection 53 in such manner as to provide arestricted annular opening 6| about the end of the frusto-conicalprojection 53 and the jets 54, 55,-'which opening communicates with theannular chamber 62 between the projection and the cap. The cap 60 isprovided with two angularly directed air jets 63, 63, adapted to producea fan type spray, which communicate with a passage 64- leading throughthe gun frame to a valve 65 located in the handle of the gun andoperated by movement of a valve stem 66. From the valve 65, a passage 61leads to an external connection 68. to which a compressed air line 69may be connected. The annular chamber 62 communicates at the point 10with the aforesaid air passage 64 to supply air to the annular opening6| about the two fluid jets 54, 55, when air is flowing through the gunto the air jets 53, 63. The two fluid jets 54 and 55 normally are closedby a pair of needle valves 12, 13 which extend back through the gunframe and which are resiliently urged against the jet valve seat bymeans of coil springs ll, 15. For operating the air valve 65 and the twoneedle valves 12, 13 in desired succession, a trigger lever I6 ispivoted at a point 11 upon the gun frame so that the lever in its normalposition rests against the end of the valve stem 65 when the air valve65 is closed. The lever 16 is provided with a slot 18 which engages apin I9 upon the stem of the needle valve 12 in such manner as to movethe valve stem and to open the jet 54 after the trigger lever has beendepressed a short distance suflicient to open the air valve 65 and toallow air to flow through the gun. As the trigger lever 16 is furtherdepressed, it engages a block so mounted upon the stem of the secondneedle valve I3 and so opens the jet 55 to permit fluid to issuetherefrom. Thus, it is seen that as the trigger lever is depressed thethree valves 65, I2, and I3 are opened in succession and likewise as thelever is returned to its normal position by resilient pressure appliedby the coil spring 8! about the valve stem 56, the three valves areclosed in reversed succession.

A slightly modified form of spray head, illustrated in Fig. 3, may beused upon a gun similar to the one hereinabove described, to secureexceptionally intimate mixing oi the latex and the coagulant. Such aspray head comprises the usual cylindrical cap 81, adapted to be clampedor screwed onto the end of a spray gun. and having two angularlydirected air Jets 8!, 8! disposed at diametrically opposed points uponthe cap, the jets being so directed that air streams issuing therefromwill converge at a point in front of the gun. The cap likewise has acentral circular opening which is slightly larger than a projecting nose84 of the gun about which the opening flts to provide a restrictedannular outlet 85 from which air may issue. In the center.

of the projection 84 is provided a latex jet 55, and in closelyrelationed positions thereto, a pair of coagulant jets 81, 81, locatedone on each side of the latex jet and in a line with the air jets 83,83. In using such a spray head, the latex stream issuing from thecentral jet is surrounded by the two coagulant streams and the latex andcoagulant are intimately admixed and broken into a directed fan spray bythe air streams issuing from the annular outlet and the two angularlydirected jets. Other arrangements of the various fluid jets obviouslyare possible.

constructional details of the spray gun and head have been omitted forclarity of illustration but may be supplied by one familiar with suchequipment.

In using the spray gun 50 for applying temporary protective coatingsaccording to the present invention, fluid coagulant is supplied by meansof the connection 58 to the jet 54 and latex likewise is suppliedthrough the connection 59 to the jet 55, both liquids being suppliedunder slight pressure as by gravity feeding. Compressed air at a.pressure of 20 to 50 pounds per square inch is supplied by means of theconnection 68. The spray head of the gun is brought to a point aboutfour tosix inches removed from the surface to be coated and the triggerlever 16 is depressed, opening the three valves in succession asdescribed and thereby causing air to issue first from the jets 63, 63and from the annular opening 6|, followed almost immediately by fluidcoagulant from the jet 54 to produce a coagulant cloud between the gunand the article, and later foljected through the coagulant cloud wherethe latex and coagulant are thoroughly mixed and then deposited upon thesurface of the article. When coating of thearticle has been completed,the trigger lever is released which closes first the latex valve, thenthe coagulant valve, and finally the air valve so that no latex canpossibly be deposited upon the article without flrst being treated withcoagulant.

The fluid coagulant utilized in this invention may be any fluid capableofcoagulating or other- 'wise materially altering the flowing propertiesof the rubber latex or analogous aqueous dispersion under the conditionsof operation hereinabove described and which itself is not injurious tothe material to be coated. The fluid coagulant for example may be acoagulating gas such as carbon dioxide, a highly volatile liquidcoagulant such as alcohol or acetone, a less volatile liquid such asformic or acetic acid solution, or even a mineral acid solution such asa solution of hydrochloric or sulfuric acid although such acidsgenerally are not desirable because of their greater corrosive action,or the coagulant may be a solution of a coagulating salt in a suitableliquid vehicle,

for example, a solution of a salt of a polyvalent metal such as zincnitrate, calcium chloride, barium chloride, calcium acetate. calciumnitrate,

etc., in a suitable solvent which may be water one of the aforesaidfluid jets to a separate fluid materials which are easily spotted anddiscolored,

a coagulant solution containing grams of barium chloride per 100 cc. ofwater has been found to be exceptionally satisfactory as regards absenceof spotting and discoloration as well as the production of acoagulatedrubber coating of the desired properties. The proportion ofbarium chloride may be varied from about 10 grams per 100 cc. up to thelimit of its solubility in water which is about 40 grams per 100 cc. Incoating kid and similar leathers a coagulant consisting of about 10 cc.of glacial acetic acid per 100 cc. of water has been found satisfactory.

. As has been indicated, the "latex employed in this invention may beany natural or artificial aqueous dispersion of rubber, includingcaoutchouc, balata, gutta percha, synthetic rubber and like materials,or any analogous coagulable dispersion of other material having suitableproperties, such as a wax dispersion, and such dispersions may beconcentrated, diluted, thickened, thinned, vulcanized or unvulcanized asdesired, and may contain any desirable compounding materials.

Numerous modifications and variations may be made in details of theinvention as hereinabove described without departing from the scope ofthe discovery as indicated by theappended claims.

I claim:

1. In an apparatus for applying a coating of latex to an article, meansfor spraying coagulant to produce a cloud thereof, means for sprayinglatex through said cloud and onto said article, a needle valvecontrolling said coagulant spraying means, a second needle valvecontrolling the latex spraying means, and a single means for operatingthe two needle valves in a predeter-- mined successive order the valvecontrolling the coagulant spraying means being opened prior to theopening of the valve controlling the latex spraying means and the valvecontrolling the latex spraying means being closed prior to the closingof the valve controlling the coagulant i spraying means.

2. In an apparatus for producing a cloud of coagulant and for projectinglatex in finely divided form through said cloud, a multiple spray guncomprising means for producing a blast of air, means 'for directingastream of fluid coagulant into said blast of air to produce a coagulantcloud, means for projecting latex into said blast .of air and coagulantcloud, controlling means for each of the aforesaid means, and a singlemeans for successively operating each of said controlling means, all theconstituent parts of said multiple spray gun being arranged within asingle pray gun body.

3. Apparatus for interminglmg and spraying a plurality of differentfluids including at least one liquid material, which comprises a spraygun having a single spray head, an angularly directed fluid jet in saidhead, at least two other fluid jets including at least one liquid jet sopositioned in said head as to cause fluid streams lSSlllllg therefrom toconverge at a point removed from said head with a fluid stream issuingfrom the aforesaid angularly directed jet, at least three separate fluidconduits, each of which leads from reservoir and at least one of which.ieads to a liquid reservoir, at least three valves located one in eachof said conduits, and a single means for operating saidvalvessuccessiv'elyso that the valves are opened in successive order andclosed in reversed successive order.

4. Apparatus for spraying a plurality of different liquids, saidapparatus comprising means for separately discharging concurrently atleast two diflerentliquids and means for discharging air or similarmaterial to atomize at least one of the discharged liquids, all saiddischarge means being arranged within a single spray gun body, and asingle control means effective to operate the said discharge means in apredetermined order and to operate at least two of said discharge meansin predetermined timed succession.

5. Apparatus for spraying a plurality of fluids including at least twodifferent liquids in co- -mingling relation, said apparatus including atof them in timed succession, the valves opened in timed successionincluding those controlling discharge of the aforesaid two liquids.

6. Apparatus for spraying a plurality of fluid s including at least twodifferent liquids in comingling relation, said apparatus including atleast three valves, each controlling discharge of a different fluid, anda single means for operating all the said valves in predetermined timedsuccession.

7. Apparatus for spraying a plurality of fluids including at least twodifferent liquids in comingling relation, said apparatus'including atleast three valves,'each controlling discharge of a different fluid, anda single means for opening and closing all the said valves inpredetermined timed succession.

8. A spray gun for spraying and atomizing a plurality of difierent.liquids and for causing thev atomized liquids to commingle, said gunconsisting of a single spray gun body adapted to be held in one hand byan operative, a single spray head on said body, said spray head havingtwo separate liquid discharge ports arranged in closely relationedside-by-side positions so as to discharge streams of diflerent liquidsin substantially parallel paths, separate needle valves controllingdischarge of liquids from the aforesaid two ports, said spray head alsohaving air discharge means arranged about the aforesaid liquid dischargemeans in such manner as to cause the separate streams of differentliquids to become atomized and commingled, a valve controlling flow ofair to said air discharge means, and a single control member adapted tobe actuated by the supporting hand of the operative, said single controlmember being operatively connected to the aforesaid three valves in suchmanner as to effect opening and closing thereof in a pre-determinedtimed succession.

9. Apparatus for spraying a plurality of liquids comprising means forseparately discharging concurrently at least two different liquids andmeans for discharging air or similar material to atomize at least one ofthe discharged liquids, all said discharge means being arranged in asingle spray head within a single spray gun body.

10. Apparatus for spraying a plurality of liquids comprising means forseparately discharging concurrently at least two different liquids,means for discharging air or similar material to atomize at least one ofthe discharged liquids, all said discharge means being arranged in asingle spray head within a single spray gun body, and a single controlmeans for operating at least two of the discharges in a predeterminedsuccessive order.

11. Apparatus for spraying a plurality of liquids comprising at leasttwo separate liquid discharge means and means for discharging air orsimilar material to atomize at least one of the discharged liquids, allsaid discharge means being arranged within a single spray gun body, anda single control means for operating all the said discharge means in apredetermined successive order.

12. Apparatus for spraying a plurality of liquids comprising at leasttwo separate liquid discharge orifices disposed in relatively closerelationship and directed so as to discharge the liquids in generallyparallel directions, and means for discharging air or similar materialin such manner as to effect intermingling oi. the liquids dischargedirom the aforesaid two orifices.

13. Apparatus for spraying a plurality of liquids comprising a sprayhead having at least two separate liquid discharge orifices adapted.respectively, to discharge one of at least two diflerent liquids, saidorifices being disposed in close relationship and the spray head alsohaving an annular orifice encircling both the aforesaid liquid dischargeorifices for discharging a third fluid such as air to effect atomizationand intermingling of the liquids discharged by the first two orifices.

14. Apparatus for spraying a plurality of liquids comprising a singlespray gun body adapted to be held in a single hand by an operative andincluding means for separately discharging at least two sprayable liquidmaterials at the same time, means for discharging air or similarmaterial to modify the spray of at least one of the two liquidmaterials, and a single control means operable by the supporting handfor eil'ecting starting and stopping of the discharges of air and liquidmaterials.

15. Apparatus for spraying a plurality of liquids comprising a singlespray gun body adapted to be held in a single hand by an operative andincluding means for separately discharging at least two sprayable liquidmaterials, means for discharging air or similar material to modify thespray of at least one or the two liquid materials, and a single controlmeans operable by the supporting hand for effecting starting andstopping of the discharges of air and liquid materials in apredetermined successive order.

16. Apparatus for spraying a plurality of fluids, said apparatuscomprising a single spray gun body adapted to be held in one hand by anoperator, said spray gun body embracing means for separately receivingand separately but concurrently discharging in commingling relation atleast three different fluid materials including at least two sprayableliquid materials, and a single control means for operating at least twoof the discharging means in a predetermined successive order.

17. Apparatus for spraying a plurality of fluids, said apparatuscomprising means for separately receiving at least three diflerent fluidmaterials including air or similar material and at least one sprayableliquid material, and means for discharging said materials separately butconcurrently, the discharging means including at least two separatefluid discharge oriflces disposed in relatively close relationship anddirected to discharge two fluids, including the liquid, in generallyparallel paths, and means for discharging the air or similar material insuch manner as to effect intermingling of the fluids discharged from theaforesaid two orifices.

mam E. HANSEN.

